Side light led troffer tube

ABSTRACT

Side light LED troffer tube. In an aspect, a side light LED tube is provided that includes a tube having at least one light receiving portion configured to receive light and gradient optics formed on the tube. The gradient optics providing a transparency gradient configured to distribute the light to achieve a selected emitted light intensity variation across a selected surface of the tube.

CLAIM OF PRIORITY UNDER 35 U.S.C. § 119

This patent application claims the benefit of priority from U.S.Provisional Patent Application No. 61/423,018, entitled “SIDE LIGHT LEDTROFFER TUBE” filed on Dec. 14, 2010, and assigned to the assigneehereof and hereby expressly incorporated by reference herein.

BACKGROUND Field

The present application relates generally to light emitting diodes, andmore particularly, to a side light LED troffer tube that providesselectable light distribution using LED light sources.

Background

A light emitting diode comprises a semiconductor material impregnated,or doped, with impurities. These impurities add “electrons” and “holes”to the semiconductor, which can move in the material relatively freely.Depending on the kind of impurity, a doped region of the semiconductorcan have predominantly electrons or holes, and is referred to as ann-type or p-type semiconductor region, respectively.

In LED applications, an LED semiconductor chip includes an n-typesemiconductor region and a p-type semiconductor region. A reverseelectric field is created at the junction between the two regions, whichcauses the electrons and holes to move away from the junction to form anactive region. When a forward voltage sufficient to overcome the reverseelectric field is applied across the p-n junction, electrons and holesare forced into the active region and combine. When electrons combinewith holes, they fall to lower energy levels and release energy in theform of light. The ability of LED semiconductors to emit light hasallowed these semiconductors to be used in a variety of lightingdevices. For example, LED semiconductors may be used in general lightingdevices for interior or exterior applications.

A troffer is a light fixture resembling an inverted trough that istypically either recessed in, or suspended from, the ceiling. Troffersare typically designed to emit light using fluorescent lighting tubes.The fluorescent tubes emit light along the entire length of the trofferto produce a desirable light distribution pattern. Unfortunately,fluorescent lighting tubes may be unreliable, require a warm up period,and produce poor color quality and flicker that people may findundesirable. Thus, LEDs are attractive candidates for replacingfluorescent lighting tubes in troffers. For example, LEDs have no warmup time, are long lasting and power efficient, and do not flicker.

However, LEDs are considered to be a point light source in that thelight is emitted from a relatively small region. Thus, utilizing LEDs introffers present various design challenges since it is desirable tocontrol the intensity of light emitted across the length of the troffer.For example, it may be desirable to have uniformly distributed lightintensity across the length of the troffer. One technique for using LEDsto obtain uniformly distributed light intensity across the length of thetroffer is to use a large number of LEDs that are distributed throughoutthe troffer. Unfortunately, this technique results in a complex trofferdesign and the cost of utilizing a large number of LEDs may beprohibitive.

Accordingly, what is needed is a simple and cost efficient way to useLED semiconductors in troffers and to control the intensity of lightemitted from the troffer.

SUMMARY

In various aspects, a side light LED tube is provided that can beconfigured to control the intensity of light emitted across the surfaceof the tube. For example, the tube can be used in a troffer housing andconfigured to uniformly distribute light emitted from LED semiconductorsmounted at the ends of the tube. In various implementations, the tubecomprises gradient optics that are configurable to provide atransparency gradient that operates to control the intensity of lightemitted across the surface of the tube. Thus, the gradient optics can beconfigured to produce uniform light intensity from the tube. In otherimplementations, the gradient optics can be configured to providecontrollable distribution of emitted light intensity across the surfaceof the tube.

In one implementation, the tube also provides integrated power/thermalmanagement module and is socket ready to fit into standard troffersockets used in troffer housings. As a result, the side light LED tubecan be easily installed in a troffer housing to provide configurabledistribution of light intensity, such as uniform light intensity, fromthe troffer tube.

In an aspect, a side light LED tube is provided that comprises a tubehaving at least one light receiving portion configured to receive lightand gradient optics formed on the tube. The gradient optics providing atransparency gradient configured to distribute the light to achieve aselected emitted light intensity variation across the surface of thetube.

It is understood that aspects of the present invention will becomereadily apparent to those skilled in the art from the following detaileddescription. As will be realized, the present invention includes otherand different aspects and its several details are capable ofmodification in various other respects, all without departing from thespirit and scope of the present invention. Accordingly, the Drawings andDescription are to be regarded as illustrative in nature and not asrestrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects described herein will become more readily apparentby reference to the following Description when taken in conjunction withthe accompanying drawings wherein:

FIG. 1 shows an exemplary side light LED troffer tube that providescontrollable distribution of emitted light intensity;

FIG. 2 shows a cross-sectional view of the side light LED troffer tubeof FIG. 1;

FIG. 3 shows exemplary implementations of a gradient optics surfacesuitable for use with the side light LED troffer tube;

FIG. 4 illustrates an exemplary implementation of a troffer tube;

FIG. 5 shows an exemplary integrated power and thermal managementmodule;

FIG. 6 shows an exemplary troffer housing suitable for use with a sidelight LED troffer tube;

FIG. 7 shows an exemplary assembly comprising the housing of FIG. 6 andthe side light troffer tube of FIG. 1;

FIG. 8 illustrates how an exemplary side light troffer tube can beconfigured in a non-linear configuration;

FIG. 9 shows an exemplary perspective view of a non-linear troffer tube;

FIG. 10 shows an exemplary side light assembly; and

FIG. 11 shows top views of exemplary lighting devices formed from theside light assembly shown in FIG. 10.

DESCRIPTION

The present invention is described more fully hereinafter with referenceto the accompanying drawings, in which various aspects of the presentinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to the variousaspects of the present invention presented throughout this disclosure.Rather, these aspects are provided so that this disclosure will bethorough and complete, and will fully convey the scope of the presentinvention to those skilled in the art. The various aspects of thepresent invention illustrated in the drawings may not be drawn to scale.Accordingly, the dimensions of the various features may be expanded orreduced for clarity. In addition, some of the drawings may be simplifiedfor clarity. Thus, the drawings may not depict all of the components ofa given apparatus (e.g., device) or method.

Various aspects of the present invention will be described herein withreference to drawings that are schematic illustrations of idealizedconfigurations of the present invention. As such, variations from theshapes of the illustrations as a result, for example, manufacturingtechniques and/or tolerances, are to be expected. Thus, the variousaspects of the present invention presented throughout this disclosureshould not be construed as limited to the particular shapes of elements(e.g., regions, layers, sections, substrates, etc.) illustrated anddescribed herein but are to include deviations in shapes that result,for example, from manufacturing. By way of example, an elementillustrated or described as a rectangle may have rounded or curvedfeatures and/or a gradient concentration at its edges rather than adiscrete change from one element to another. Thus, the elementsillustrated in the drawings are schematic in nature and their shapes maynot be intended to illustrate the precise shape of an element and arenot intended to limit the scope of the present invention.

It will be understood that when an element such as a region, layer,section, substrate, or the like, is referred to as being “on” anotherelement, it can be directly on the other element or intervening elementsmay also be present. In contrast, when an element is referred to asbeing “directly on” another element, there are no intervening elementspresent. It will be further understood that when an element is referredto as being “formed” on another element, it can be grown, deposited,etched, attached, connected, coupled, or otherwise prepared orfabricated on the other element or an intervening element.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or“top,” may be used herein to describe one element's relationship toanother element as illustrated in the drawings. It will be understoodthat relative terms are intended to encompass different orientations ofan apparatus in addition to the orientation depicted in the Drawings. Byway of example, if an apparatus in the Drawings is turned over, elementsdescribed as being on the “lower” side of other elements would then beoriented on the “upper” sides of the other elements. The term “lower”,can therefore, encompass both an orientation of “lower” and “upper,”depending of the particular orientation of the apparatus. Similarly, ifan apparatus in the drawing is turned over, elements described as“below” or “beneath” other elements would then be oriented “above” theother elements. The terms “below” or “beneath” can, therefore, encompassboth an orientation of above and below.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andthis disclosure.

As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof. The term “and/or” includes any andall combinations of one or more of the associated listed items

It will be understood that although the terms “first” and “second” maybe used herein to describe various regions, layers and/or sections,these regions, layers and/or sections should not be limited by theseterms. These terms are only used to distinguish one region, layer orsection from another region, layer or section. Thus, a first region,layer or section discussed below could be termed a second region, layeror section, and similarly, a second region, layer or section may betermed a first region, layer or section without departing from theteachings of the present invention.

FIG. 1 shows an exemplary side light LED troffer tube 100 that providescontrollable distribution of emitted light intensity. For example, thetroffer tube 100 can be configured to provide uniform light intensityacross the surface of the tube 100. The tube 100 comprises optics tube102, end mounted LEDs 104 and 106, and integrated power/thermalmanagement modules 108. It should be note that aspects of gradientoptics described herein are suitable for use with virtually any type oflighting device and are not limited to only implementations of a troffertube. Thus, the descriptions of the troffer tube herein provideexemplary implementations but are not intended to limit the variousaspects to only those implementations.

The optics tube 102 comprises a tube having first and second ends. Eachend is configured to have a light receiving portion that receives lightto be emitted from the tube 102. In one implementation, the lightreceiving portion is configured to receive light from an LED lightsource.

The tube 102 comprises an upper portion with an interior surface 110 andan exterior surface 112. The tube 102 also comprises a lower portionwith an interior surface 114 and an exterior surface 116. In variousimplementations, one or both of the surfaces 110, 112 of the upperportion are reflective so as to reflect light emitted from the LED lightsources 104, 106 back into the tube 102. Furthermore, one or both of thesurfaces 114, 116 of the lower portion comprise gradient optics thatoperate to control the intensity of light emitted from the tube 102. Forexample, light emitted from the LED sources 104, 106 strikes thereflective interior surface 110 and is reflected toward the gradientoptics provided at the surface 114. The gradient optics provides atransparency gradient, shown generally at 118, to control the intensityof the light emitted from the tube 102. In one implementation, thegradient optics are configured to provide uniform light intensity fromthe tube 102, as indicated at 132. In other implementations, thegradient optics are configured to provide controllable emitted lightintensity variations across the surface of the tube 102.

It should also be noted that although the optic tube 102 comprises around shape; the optics tube 102 can be configured to have a shapeselected from a set of shapes comprising circular, oval, elliptical,parabolic, and multisided shapes. Thus, it is possible for the optictube 102 to have a cross section forming any type of shape and to haveany desired length. For example, the length may be selected to provide atroffer tube that is compatible (i.e., replaceable) with standardflorescent tubes, such as standard T8 or T12 fluorescent tubes.

An integrated power/thermal management module 108 is coupled at each endof the tube 102 and is designed to provide power and thermal managementto the LED light sources 104, 106. To facilitate installation in atroffer housing, the integrated power/thermal management modules 108comprise connectors 120 that includes electrical contacts designed tomate with conventional troffer sockets. For example, the connector 120is configured to connect to standard troffer sockets typically used forfluorescent lighting tubes. The connector 120 can be orientated in anyfashion so that when the tube 102 is installed and connected in atroffer housing, the surfaces 110 and 112 are above the surfaces 114 and116 so that emitted light is directed and distributed downward. However,in other implementations, the connector 120 can be orientated in anyposition relative to the surfaces 110, 112 and 114, 116.

Thus, the overall length of the LED troffer tube 100 is configured sothat it can be an equivalent or replacement for standard fluorescentlight tubes. It should be noted that in various implementations, the LEDtroffer tube 100 may be configured to have any desired dimension, shape,and/or length.

The gradient optics is provided at one or both of the surfaces 114 and116. In various implementations, the gradient optics operates to controlthe intensity of light emitted across the surface of the tube 102. Forexample, in one implementation, the gradient optics provides atransparency gradient that results in less transparency towards the endsof the optics tube 102 and more transparency toward the centerline 122of the optics tube 102, resulting in even distribution of emitted lightintensity across the surface of the tube 102.

Transparency graph 118 illustrates how the gradient optics at thesurfaces 114, 116 of the optics tube 102 are designed to provide thetransparency gradient. For example, at regions 124 and 126 located nearthe ends of the optics tube 102, the transparency of the optics tube 102is reduced. At region 128, near the center of the optics tube 102, thetransparency is increased. Thus, the gradient optics are configured toallow more light to pass through the center of the optics tube 102 thanat its ends to provide for uniform emitted light intensity across thesurface of the optics tube 102.

To further illustrate the operation of the troffer tube 100 to provideconfigurable light intensity along its length, a cross section indicator130 indicates a cross sectional of the tube 100 that is discussed infurther detail below. It should be noted that although the gradientoptics can be configured in a variety of ways to control the emittedlight intensity from the tube 100; for the purpose of this description,the gradient optics have been configured to provide uniform lightintensity across the surface of the tube 100. However, in otherimplementations, the gradient optics can be configured to provide anydesirable light intensity distribution pattern.

FIG. 2 shows a cross-sectional view 200 of the side light LED troffertube 100 shown of FIG. 1. For example, the view 200 is taken at crosssection indicator 130. The optics tube 102 comprises an upper portion202 and a lower portion 204. The upper portion 202 comprises theinterior surface 110 and exterior surface 112. The lower portion 204comprises the interior surface 114 and exterior surface 116. In variousimplementations, gradient optics are formed or disposed on one or bothof the interior surface 114 and exterior surface 116. For example,gradient optics provided lengthwise along the tube 102 are shown in thecross-sectional view 200 as the regions 206, 208, 210, 212, and 214.Light emitted from the LED source 104 reflects off the reflectivesurface 110 and passes through the gradient optics disposed at thesurface 114. As a result, the intensity of light emitted across thesurface of the tube 100 can be controlled.

In one embodiment, the optics tube 102 is made from glass, acrylic orplastic material and the gradient optics disposed on the surface 114and/or 116 can be formed in any of several ways to provide a desiredtransparency gradient. For example, the transparency gradient providedby the gradient optics formed on the surface 114 and/or 116 may beobtained using material thickness variation, material variation, thinfilm applications, material density variations, material layering,surface texturing and/or surface defects. Furthermore, the optics tube102 may comprise any desired cross sectional shape to facilitate thedesired light distribution pattern.

FIG. 3 shows exemplary implementations 300 of gradient optics formed ordisposed on the surface 114 and/or the surface 116 of the optics tube102. For example, in any of the exemplary implementations 300 thegradient optics may be provided on one or both surfaces as discussedbelow.

In a first exemplary implementation 302, the gradient optics 306 areformed on the interior surface 114 of the optics tube 102. The gradientoptics 306 comprise sections of material having varying materialthicknesses (indicated at 308) to produce the transparency gradient. Forexample, the gradient optics 306 comprises one or more sections ofmaterial to provide more thickness at the ends of the optics tube 102than in the center region. Thus, the thickness of the material providesgradient optics 306 having decreased transparency with increasingdistance from the center line 304. The increasing material thicknessprovides the transparency gradient illustrated at 324.

It should be noted that although shown as increasing material thickness,the gradient optics 306 may comprise material of varying densities whichdo not change the overall material thickness but accomplish the sametransparency result. In another implementation, material variations areused to provide the transparency gradient. The material variationscomprise different types of material that are layered as illustrated at308 to provide the desired transparency gradient. Thus, the gradientoptics 306 can be provided by any combination of material thickness,material variation, material layering, and/or material density.

In a second exemplary implementation 310, the gradient optics 312 areformed on the interior surface 114 of the optics tube 102. The gradientoptics 312 comprise a surface coating that provides the transparencygradient illustrated at 324. The surface coating may be formed using avariety of techniques. For example, the surface coating may be adiffuser film applied to the tube or a polymer material that is paintedonto the tube. The surface coating is designed to provide moretransparency near the center line 304, as illustrated by the lightregion 314, and less transparency as the distance from the center lineincreases, as illustrated by the dark region 316. The differenttransparency regions of the surface coating provide the transparencygradient illustrated at 324. In another implementation, the gradientoptics 312 comprises sections of different materials, where eachmaterial provides a different transparency to achieve the transparencygradient 324.

In a third exemplary implementation 318, the gradient optics 320 areformed on the interior surface 114 of the optics tube 102. The gradientoptics 320 comprise surface texturing that provides one or more surfacefeatures 322. The surface features 322 may be ridges, bumps or othersurface features that are arranges in any desired pattern and/or spacingto provide the transparency gradient illustrated at 324. For example, inone implementation, the surface features 322 comprise ribs that aregradually less concentrated near the center line 304 to provide fordecreased transparency as the distance from the center line 304increases.

In a fourth exemplary implementation 326, the gradient optics 328 areformed on the interior surface 114 of the optics tube 102. The gradientoptics 328 comprise surface texturing that provides one or more surfacedefects, as illustrated at 330. The surface defects 330 comprisescratched or sanded regions or other defects in the interior surface 114which affect light distribution. The surface defects are arranged in anydesired pattern and/or spacing to provide the transparency gradientillustrated at 324. For example, more surface defects are provided nearthe center line 304 to increase transparency. Less surface defects areprovided as the distance from the center line 304 increases to decreasetransparency.

In a fifth exemplary implementation 332, the gradient optics 334 and 336are formed on the interior surface 114 and the exterior surface 116 ofthe optics tube 102. The gradient optics 334 comprise a surface coatingthat provides the transparency gradient illustrated at 324. The surfacecoating may be formed using a variety of techniques. For example, thesurface coating may be a diffuser film applied to the acrylic or apolymer material that is painted onto the acrylic. The surface coatingis designed to provide more transparency near the center line 304 andless transparency as the distance from the center line increases.

The gradient optics 336 comprise surface texturing that provides one ormore surface defects. The surface defects comprise scratched or sandedregions or other defects in the exterior surface 116 which affect lightdistribution. The surface defects are arranged in any desired patternand/or spacing to provide the transparency gradient illustrated at 324.For example, more surface defects are provided near the center line 304to increase transparency. Less surface defects are provided as thedistance from the center line 304 increases to decrease transparency.Thus, the fifth implementation 332 illustrates how gradient optics canbe formed on both the interior surface 114 and the exterior surface 116to provide the transparency gradient illustrated at 324.

It should be noted that although five exemplary implementations ofgradient optics are shown, other implementations of gradient optics maybe formed on the optic tube 102 to provide the transparency gradient324. Furthermore, implementations of the gradient optics can beconfigured to provide transparency gradients that are different from thetransparency gradient 324. For example, the gradient optics can beconfigured to provide any desirable transparency gradient to control thelight intensity emitted along the length of the tube 100. Thus, thegradient optics may be formed individually or formed in any combinationon the interior and/or exterior surface of the optic tube to produce thetransparency gradient 324 or other desired transparency gradients.

Gradient Optics Performance

In various implementations, the gradient optics provides a transparencygradient that operates to control the light intensity emitted from theLED troffer tube. For example, the transparency gradient can beconfigured to provide uniformly distributed light intensity emitted fromthe LED troffer tube. The gradient optics may be formed and/or disposedon the troffer tube using one or more of the implementations discussedwith respect to FIG. 3 to achieve a light output having a desired lightintensity distribution.

Thus, in one implementation of the gradient optics, the variation inlight intensity emitted from the optics tube is configured to vary bysubstantially 100 per cent. In this implementation, the gradient opticsare configured to provide at least one surface region wheresubstantially no light is emitted from the optics tube, and at least oneother surface region where a maximum amount of light is emitted from theoptics tube. This configuration results in substantially a 100 per centvariation in the intensity of emitted light.

In other implementations of the gradient optics, the variation in lightintensity emitted from the optics tube is configured to vary by anyamount less than 100 per cent. For example, the gradient optics can beconfigured to provide any desired variation in light intensities acrossthe surface regions of the optics tube to achieve a desired emission orcorresponding illumination pattern.

FIG. 4 illustrates an exemplary implementation of a tube 400 comprisinggradient optics. The tube 400 comprises a lower tube portion 402 coupledto an integrated power and thermal management module 414.

The integrated power and thermal management module 414 comprises an LED416 that emits light along the length of the tube 400 as indicated bythe dashed lines. The module 414 provides power to the LED 416 andregulates the dissipation of heat generated by the LED 416. Alsoillustrated is LED 418, which emits light along the length of thetroffer 400 from the end opposite of the LED 416, as indicated by thedashed lines. For clarity, a corresponding integrated power and thermalmanagement module associated with the LED 418 is not shown.

The lower tube portion 402 comprises gradient optics formed on aninterior surface. In this example, the gradient optics are formed usinga thin film application onto the interior surface. For example, the thinfilm application provides multiple gradient optic surface regions andeach region provides a selected transparency. The tube 402 is dividedinto crosswise sections that extend across the tube 102, as illustratedat 404, 406, 408, 410, and 412. The tube 402 is also divided intolengthwise sections that extend along the length of the tube, asillustrated at 420, 422, 424, and 426. The crosswise and lengthwisesections define surfaces of the tube 402 having gradient optics thatprovide selected transparency gradients. For example, crosswise surfaceregions include 428, 430, 432 and 434 and lengthwise surface regionsinclude 436, 438, 430, 440, and 442. Each of the crosswise andlengthwise surface regions are configured with gradient optics toprovide a corresponding transparency gradient that allows light emittedfrom the LEDs 416 and 418 to pass through the lower tube portion 402with a selected intensity characteristic.

The transparency graph 444, illustrates the transparency provided by thegradient optics at the surfaces of the lengthwise section 422. Forexample, the surface regions 436 and 442 provide the least transparency,the surface regions 438 and 440 provide additional transparency and thesurface region 430 provides the most transparency. The gradient opticsprovided at the regions 436, 438, 430, 440 and 442 operate to controlthe intensity variation of light emitted across the identified surfacesof the tube 402.

The transparency graph 446, illustrates the transparency provided by thegradient optics at the surfaces of the crosswise section 408. Forexample, the surface regions 428 and 434 provide the least transparencyand the surface regions 430 and 432 provide additional transparency. Thegradient optics provided by the surface regions 428, 430, 432, and 434operates to control the intensity variation of light emitted across theidentified surfaces of the tube 402.

It should be noted that gradient optics can be provided on any number ofsurface regions to create any desired transparency characteristicsacross the surface of the tube. Thus, the tube 402 is configured withcrosswise and lengthwise surfaces having respective gradient opticsformed on one or both of the interior and exterior surfaces of the tube.The gradient optics provide a transparency gradient provided at eachsurface region is configured to distribute light to achieve a selectedemitted light intensity variation across the surface of the tube.

FIG. 5 shows an exemplary integrated power and thermal management module500. For example, the module 500 is suitable for use as the module 108shown in FIG. 1. The module 500 comprises a connector 502, power supply504, LED 506, and thermal management circuit 508.

The connector 502 is configured to provide a mechanical and electricalcoupling to a socket in a troffer housing. For example, the connector502 is configured to connect to a standard fluorescent light tubeconnector in a troffer housing and carry electric signals comprisingpower and/or control signals to the power supply 504.

The power supply 504 is configured to receive the input electricalsignals and generate a power signal to the LED 506. The power supply 504may convert, amplify, attenuate or perform other functions to the inputelectrical signals to produce the power signal that is provided to theLED 506.

The LED 506 comprises any suitable LED for use in a troffer tube. Thethermal management circuit 508 operates to receive thermal indicatorsassociated with the operation of the LED 506 and provide control signalsto the power supply 504 to adjust the power signal provided to the LED506. The thermal management circuit 506 may also provide a heat sink toallow dissipation of heat from the LED 506. Thus, the thermal managementcircuit 508 operates to receive a thermal feedback indicator and adjustand manage the power supply 504 to control the temperature of the LED506.

It should be noted that the integrated power and thermal managementmodule 500 illustrates just one implementation and that otherimplementations that combine or redistribute the described functions arepossible.

FIG. 6 shows an exemplary troffer housing 600 suitable for use with theside light LED troffer tube 100 shown in FIG. 1. The troffer housing 600comprises a housing 602 that is illustrated in side 604, bottom 606 andend 608 views. For example, the housing may be a 2′×6′ housing typicallyused for fluorescent lighting.

Referring to the bottom view 606, the housing 602 comprises an internalreflective surface 610 which is designed to reflected light to thebottom portion of the housing. Referring to the end view 608, thereflective surface 610 is more clearly shown.

The housing 602 comprises two sockets 612 mounted therein. The sockets612 are spaced apart from each other and configured to mate with theconnectors 120 of the side light LED troffer tube 100. Thus, the sidelight LED troffer tube can be mechanically and electrically coupled tothe apparatus 600 to produce evenly distributed light from end mountedLEDs.

FIG. 7 shows an exemplary troffer assembly 700 comprising the trofferhousing 600 of FIG. 6 and the side light LED troffer tube 100 of FIG. 1.For example, the troffer assembly 700 is suitable for use as an internallighting device, such as a ceiling light. In the troffer assembly 700,the side light LED troffer tube 100 is coupled to the connectors 612 atthe bottom portion of the housing 602. It should be noted that the sidelight LED troffer tube 100 provides a transparency gradient configuredto provide for even light distribution.

During operation, light is emitted from the side light LED troffer tube100 in an intensity distribution pattern as indicated at 702. Forexample, light is emitted from the end mounted LEDs within the troffertube and passes through a transparency gradient provided by the gradientoptics of the troffer tube to result in the intensity distributionhaving substantially no intensity variation, as illustrated at 702.Thus, the troffer assembly 700 operates to provide evenly distributedlight from a side light LED troffer tube having an associatedtransparency gradient.

FIG. 8 illustrates how a linear side light LED troffer tube can beconfigured in a non-linear configuration. For example, it is possible toreconfigure the side light LED troffer tube 100 into the non-linear tube802. For example, sections of the linear tube 100 are shown in their newlocation at the non-linear tube 802. For instance, the section 804 isrelocated to section 806 of the non-linear tube 802. The LEDs 104 and106 are relocated to the LEDs 808 and 810. In the non-linearconfiguration 802, the LEDs 808 and 810 are positioned back-to-back andemit light into the tube 802 in different directions.

Thus, it is possible to produce various non-linear implementations ofthe linear side light LED troffer tube 100. Because FIG. 8 shows a topview of the non-linear tube 802, the transparency gradient is facingdown or into the page. Additional description of the non-linear tube 802and associated transparency gradient is provided below.

FIG. 9 shows an exemplary perspective view of the non-linear tube 802.As discussed above, the non-linear tube 802 comprises LEDs 808 and 810mounted back-to-back and emitting light into the tube 802 in differentdirections. In various implementations, the LEDs 808 and 810 may bepowered through electrical connections (not shown) or inductively.

The non-linear tube 802 comprises a top portion 902 and a bottom portion904. The top portion 902 includes a reflective interior surfaceconfigured to reflect light back toward the bottom potion 904. Thebottom portion 904 includes gradient optics (internally, externally orboth) that provide a transparency gradient as discussed above. Thetransparency gradient operates to control how the intensity of the lightemitted from the LEDs 808 and 810 is distributed. In one implementation,the transparency gradient operates to provide evenly distributed lightintensity, as indicated at 906. Although the tube 802 is configured in acircular configuration, other non-linear configurations are possible.

FIG. 10 shows an exemplary side light assembly 1000. The side lightassembly 1000 comprises an emitter portion 1002 and a gradient opticsportion 1004. The emitter portion 1002 comprises electrical connector1006, power and thermal management module 1008, and LED 1010. Thegradient optics portion 1004 comprises a tube 1012 having an upperportion with a reflective surface 1014 and a lower portion with gradientoptics 1016. The gradient optics 1016 are designed to provide atransparency gradient to control how the distribution of light intensityemitted from the tube. It should be noted that the tube 1012 may haveany cross-sectional shape, such as circular, parabolic, elliptical,triangular, or other multisided shape.

In various implementations, the assembly 1000 can be arranged andconfigured to provide a variety of lighting devices. For example, theassembly 1000 can be curved into various shapes and include multipleemitter portions 1002 or a reflective end cap. In other implementations,two or more of the assemblies 1000 can be combined to form more complexlighting devices. Several exemplary lighting devices that can be formedfrom the assembly 1000 are discussed below.

FIG. 11 shows top views of exemplary lighting devices formed from theside light assembly 1000 shown in FIG. 10. For example, each of thelighting devices is formed from one or more configurations of theassembly 1000. Each device comprises gradient optics that provides atransparency gradient to distribute the light emitted from one or moreLEDs to achieve a selected intensity variation along the length of thedevice. Since FIG. 11 shows top views, it will be assumed that thedistributed light is being emitted into the page.

A first exemplary light device 1102 is formed by curving a selectedlength of the gradient portion 1004 of the assembly 1000 to form thegradient portion 1108 and adding a reflective end cap 1104. Thereflective end cap 1104 comprises any suitable reflective material toreflect light back into the device 1102. An emitter portion 1106 emitslight into the gradient portion 1108. The gradient portion 1108comprises gradient optics that provides a transparency gradient todistribute the light to achieve a selected emitted light intensityvariation across the surface of the device 1102. For example, thegradient portion 1108 provides the transparency gradient 1110. Thetransparency gradient 1110 indicates less transparency near the emitter1106 (E) and greater transparency near the end cap (C).

A second light device 1112 is formed by curving a selected length of thegradient portion 1004 of the assembly 1000 to form the gradient portion1118. Two emitter portions 1114 and 1116 emit light into the gradientportion 1118. The gradient portion 1118 comprises gradient optics thatprovides a transparency gradient to distribute the light to achieve aselected emitted light intensity variation across the surface of thedevice 1112. For example, the gradient portion 1118 provides thetransparency gradient 1120. The transparency gradient 1120 indicatesless transparency near the emitters (E) and greater transparency nearthe midpoint (M).

A third light device 1122 is formed by combining two of the assembly1000 and curving their associated gradient portions 1004 to form twogradient portions 1124 and 1126 that include end caps 1134 and 1136. Twoemitter portions 1128 and 1130 are provided to emit light into thegradient portions 1124 and 1126. The gradient portions 1124 and 1126comprise gradient optics that provides a transparency gradient todistribute the light to achieve a selected emitted light intensityvariation across the surface of the device 1122. For example, thegradient portions 1124 and 1126 provide the transparency gradient 1132.The transparency gradient 1132 indicates less transparency near theemitters (E) and greater transparency near the end caps (C).

A fourth light device 1138 is formed by curving a selected length of thegradient portion 1004 of the assembly 1000 to form a gradient portion1140. Two emitter portions 1142 and 1144 emit light into the gradientportion 1140. The gradient portion 1140 comprises gradient optics thatprovides a transparency gradient to distribute the light to achieve aselected emitted light intensity variation across the surface of thedevice 1138. For example, the gradient portion 1140 provides thetransparency gradient 1146. The transparency gradient 1146 indicatesless transparency near the emitters (E) and greater transparency nearthe mid point (M).

A fifth light device 1148 is formed by combining two of the assembly1000 and curving their associated gradient portions 1004 to form twogradient portions 1150 and 1152 that include end caps 1154 and 1156. Twoemitter portions 1158 and 1160 are provided to emit light into thegradient portions 1150 and 1152. The gradient portions 1150 and 1152comprise gradient optics that provides a transparency gradient todistribute the light to achieve a selected emitted light intensityvariation across the surface of the device 1148. For example, thegradient portions 1150 and 1152 provide the transparency gradient 1162.The transparency gradient 1162 indicates less transparency near theemitters (E) and greater transparency near the end caps (C).

It should be noted that although the various aspects have been describedherein with respect to a troffer tube, they are equally applicable toother types of lighting devices. For example, other types of lightingdevices, such as light bulbs, luminares, automotive lighting, interiorand exterior lighting can be configured with gradient optics to providecontrollable emitted light intensity variation across the surface of theparticular lighting device. Thus, the gradient optics can beincorporated into virtually any type of lighting device to achieve adesired light emission and/or illumination pattern.

The various aspects of this disclosure are provided to enable one ofordinary skill in the art to practice the present invention. Variousmodifications to aspects presented throughout this disclosure will bereadily apparent to those skilled in the art, and the concepts disclosedherein may be extended to other applications. Thus, the claims are notintended to be limited to the various aspects of this disclosure, butare to be accorded the full scope consistent with the language of theclaims. All structural and functional equivalents to the elements of thevarious aspects described throughout this disclosure that are known orlater come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the claims.

Moreover, nothing disclosed herein is intended to be dedicated to thepublic regardless of whether such disclosure is explicitly recited inthe claims. No claim element is to be construed under the provisions of35 U.S.C. § 112, sixth paragraph, unless the element is expresslyrecited using the phrase “means for” or, in the case of a method claim,the element is recited using the phrase “step for.”

Accordingly, while aspects of a side light LED tube with associatedtransparency gradient have been illustrated and described herein, itwill be appreciated that various changes can be made to the aspectswithout departing from their spirit or essential characteristics.Therefore, the disclosures and descriptions herein are intended to beillustrative, but not limiting, of the scope of the invention, which isset forth in the following claims.

1-26. (canceled)
 27. A side light LED tube comprising: first and secondends that oppose each other; a light emitting source disposed at one ofthe first and second ends; a reflective portion extending between thefirst and second ends; and an optics portion coupled to the reflectiveportion and also extending between the first and second ends, whereinthe optics portion comprises a plurality of gradient optic regionshaving varying transparencies, wherein the respective transparencies ofthe gradient optic regions progressively increase towards a center ofthe optics portion of the tube so that light emitted from the lightemitting source appears to be substantially uniform.